Recently, as a thin-film type electroluminescent device, instead of one using an inorganic material, there has been developed an organic electroluminescent device using an organic thin film. The organic electroluminescent device usually comprises a hole-injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, and the like between a cathode and an anode and materials suitable for the individual layers have been developed.
For example, Patent Document 1 proposes an organic electroluminescent device excellent in luminance, luminous efficiency, and heat resistance, wherein an amine compound having a respective specific structure is incorporated into the hole-injection layer and the hole transport layer and tris(8-quinolinolato)aluminum is incorporated into the light-emitting layer.
However, though the device is excellent in luminance, luminous efficiency, and heat resistance to some extent, a further problem is present with regard to a life of the device.
Moreover, since tris(8-quinolinolato)aluminum is insufficient in light emission efficiency, maximum light emission luminance, and color purity, there is a problem that application thereof to a full-color display use is limited.
Furthermore, hitherto, the organic electroluminescent device has utilized fluorescent emission but it is investigated to use not the fluorescent emission but phosphorescent emission during an attempt to enhance light emission efficiency. However, in the case of using the phosphorescent emission, it is present situation that a sufficient luminous efficiency is not yet obtained.
Most of the organic electroluminescent devices using a phosphorescent molecule hitherto are characterized to use a material containing a carbazolyl group as a material for the light-emitting layer (host materials). For example, in Non-Patent Document 1, the following biphenyl derivative shown below is used as a host material.

However, the organic electroluminescent device using the above biphenyl derivative has problems in electron transporting property and durability against electric reduction.
Thus, recently, for the purpose of concentrating recombination regions in the light-emitting layer, there has been proposed a host material having both of hole transporting property and electron transporting property and, in Patent Document 2, it is described that the following compound is used in the organic electroluminescent device.

However, the organic electroluminescent device using the host material having both of hole transporting property and electron transporting property as above exhibits a tendency to incline the recombination position of charge toward the anode side and, in the case of the device using PPD or NPD as the hole transporting material, a high luminous efficiency, a high luminance, or a long driving life has not been obtained.
    Patent Document 1: JP-A-2001-316338    Patent Document 2: JP-A-6-1972    Non-Patent Document 1: Appl. Phys. Lett., Vol. 75, p. 4, 1999